* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.main-nav {
  background: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.site-logo {
  font-size: 24px;
  font-weight: 700;
  color: #1a1a1a;
  text-decoration: none;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  gap: 24px;
  flex-wrap: nowrap;
  overflow: visible;
}

.nav-links a {
  color: #666;
  text-decoration: none;
  transition: color 0.3s;
  white-space: nowrap;
  font-size: 15px;
}

.nav-links a:hover,
.nav-links a.active {
  color: #007bff;
}

.hero-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 80px 20px;
  text-align: center;
}

.hero-title {
  font-size: 32px;
  font-weight: 700;
  max-width: 900px;
  margin: 0 auto;
  line-height: 1.4;
}

.site-intro {
  background: white;
  padding: 40px 20px;
}

.site-intro p {
  max-width: 900px;
  margin: 0 auto;
  font-size: 16px;
  line-height: 1.8;
  color: #555;
}

.video-section {
  padding: 60px 20px;
}

.section-title {
  font-size: 28px;
  margin-bottom: 30px;
  color: #1a1a1a;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.video-card {
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  transition: transform 0.3s, box-shadow 0.3s;
}

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}

.video-card__link {
  text-decoration: none;
  color: inherit;
  display: block;
}

.video-cover {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  overflow: hidden;
  background: #eee;
}

.video-cover img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-info {
  padding: 16px;
}

.video-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  color: #1a1a1a;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-one-line {
  font-size: 14px;
  color: #666;
  margin-bottom: 12px;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-meta {
  display: flex;
  gap: 12px;
  font-size: 13px;
  color: #999;
}

.video-meta span {
  display: inline-block;
}

.list-main {
  min-height: 600px;
  padding: 40px 0;
}

.page-header {
  margin-bottom: 40px;
}

.page-header h1 {
  font-size: 36px;
  color: #1a1a1a;
}

.page--with-sidebar .layout-with-sidebar {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 40px;
}

.layout__side--filters {
  background: white;
  padding: 24px;
  border-radius: 12px;
  height: fit-content;
  position: sticky;
  top: 80px;
}

.layout__side--filters h3 {
  margin-bottom: 16px;
  color: #1a1a1a;
}

.top-list__items {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.top-item {
  background: white;
  padding: 20px;
  border-radius: 12px;
  display: grid;
  grid-template-columns: 60px 150px 1fr;
  gap: 20px;
  align-items: center;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.top-rank {
  font-size: 32px;
  font-weight: 700;
  color: #667eea;
  text-align: center;
}

.top-cover {
  width: 150px;
  height: 84px;
  border-radius: 8px;
  overflow: hidden;
  background: #eee;
}

.top-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.top-info h3 {
  margin-bottom: 8px;
}

.top-info h3 a {
  color: #1a1a1a;
  text-decoration: none;
}

.top-info h3 a:hover {
  color: #667eea;
}

.top-info p {
  font-size: 14px;
  color: #666;
  margin-bottom: 8px;
}

.page--grouped .group {
  margin-bottom: 60px;
}

.group__title {
  font-size: 28px;
  margin-bottom: 24px;
  color: #1a1a1a;
}

.detail-main {
  padding: 40px 0;
}

.video-player-section {
  margin-bottom: 40px;
}

.video-player {
  max-width: 900px;
  margin: 0 auto;
}

.video-player-inner {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  background: #000;
  border-radius: 12px;
  overflow: hidden;
}

.player-play-btn {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: rgba(255,255,255,0.9);
  border: none;
  cursor: pointer;
  transition: transform 0.3s, background 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.player-play-btn:hover {
  transform: translate(-50%, -50%) scale(1.1);
  background: white;
}

.player-play-icon {
  font-size: 32px;
  color: #667eea;
  margin-left: 6px;
}

.detail-header {
  margin-bottom: 32px;
}

.detail-header h1 {
  font-size: 36px;
  color: #1a1a1a;
}

.detail-info,
.detail-module,
.related-section {
  background: white;
  padding: 32px;
  border-radius: 12px;
  margin-bottom: 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.detail-info h2,
.detail-module h2,
.related-section h2 {
  font-size: 24px;
  margin-bottom: 20px;
  color: #1a1a1a;
}

.detail-info dl {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 12px;
}

.detail-info dt {
  font-weight: 600;
  color: #666;
}

.detail-info dd {
  color: #333;
}

.detail-module p {
  line-height: 1.8;
  color: #555;
}

.tags-container {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.tag {
  display: inline-block;
  padding: 6px 16px;
  background: #f0f0f0;
  border-radius: 20px;
  font-size: 14px;
  color: #666;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 20px;
}

.video-card--related .video-cover {
  padding-top: 56.25%;
}

.site-footer {
  background: #1a1a1a;
  color: white;
  padding: 40px 20px;
  text-align: center;
  margin-top: 60px;
}

.footer-content p {
  color: #999;
}

.ui-style-4 {
  --primary-color: #FF6700;
  --secondary-color: #f7f7f7;
}

.ui-style-4 .hero-section {
  background: linear-gradient(135deg, #FF6700 0%, #FF8533 100%);
}

.ui-style-4 .top-rank {
  color: #FF6700;
}

.ui-style-4 .nav-links a:hover,
.ui-style-4 .nav-links a.active {
  color: #FF6700;
}

.ui-style-4 .player-play-icon {
  color: #FF6700;
}

@media (max-width: 768px) {
  .nav-container {
    flex-direction: column;
    align-items: stretch;
    gap: 16px;
  }

  .site-logo {
    text-align: center;
    font-size: 20px;
  }

  .nav-links {
    justify-content: space-around;
    gap: 8px;
    font-size: 13px;
  }

  .hero-title {
    font-size: 24px;
  }

  .video-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 16px;
  }

  .page--with-sidebar .layout-with-sidebar {
    grid-template-columns: 1fr;
  }

  .top-item {
    grid-template-columns: 40px 100px 1fr;
    gap: 12px;
    padding: 16px;
  }

  .top-rank {
    font-size: 24px;
  }

  .top-cover {
    width: 100px;
    height: 56px;
  }

  .detail-header h1 {
    font-size: 28px;
  }

  .detail-info,
  .detail-module,
  .related-section {
    padding: 20px;
  }

  .related-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  }

  .video-cover {
    padding-top: 56.25%;
  }

  .video-card--related .video-cover {
    padding-top: 56.25%;
  }
}

@media (max-width: 480px) {
  .nav-links {
    font-size: 12px;
    gap: 4px;
  }

  .hero-section {
    padding: 40px 20px;
  }

  .video-section {
    padding: 40px 20px;
  }

  .section-title {
    font-size: 22px;
  }
}